水分胁迫期间及胁迫解除后幼年桃树光合产物的分配

Assimilates Distribution in Young Peach Plants during Water Stress and after Removing Water Stress

采用14 CO2 示踪技术 ,研究了盆栽‘京春’桃 (PrunuspersicaL .)树在水分胁迫期间和胁迫解除后光合产物在各器官间的分配。水分胁迫抑制源叶中同化产物的向外输出 ,并且在水分胁迫解除后仍对同化产物的输出具有后效作用。水分胁迫显著降低了幼年桃树幼叶 +梢尖的库活力 (14 C -光合产物分配系数K)和14 C -光合产物相对分配量 (R) ,但导致砧木韧皮部和细根K值和R值的显著增加。在水分胁迫解除后 11d ,幼叶 +梢尖K和R值获得较大程度的恢复 ,尽管仍低于对照 ,但显著高于正处于胁迫状态的植株 ,砧木韧皮部的K和R值降低到对照的水平 ,而细根的K值和R值仍维持在显著高于对照的水平上。对水分胁迫对器官碳素营养的影响与其生长的反应的关系进行了讨论。

Young peach plants(Prunus persica L.)grown in pots were studied to assess the effects of water stress on the distribution of assimilates among the organs during and after water stress by feeding leaves with 14CO_2. Water stress significantly inhibited the export of assimilates from the labeled leaves, and its‘after effect’still existed after water stress was removed. The distribution coefficient of 14C-assimilates(K)of 14C-labeled shoot segment, shoot segment below 14C-labeled shoot segment increased during water stress and remained the similar level even after removing water stress.During water stress, the K values and relative 14C-assimilate distribution(R) of young leaves and apex remarkably decreased while those of rootstock phloem and fine roots significantly increased. After water stress was removed, the K and R values were partly recovered in young leaves and apex, and they decreased to the control level in rootstock phloem. However the K and R values kept a same high level in fine roots after water stress was removed as the water-stressed plants. Moreover, the role of assimilate distribution on the organ growth response under water stress is discussed in this paper.